Research Support for Midwifery and Birth Center Care
NURSE-MIDWIVES
Nurse-midwifery is a highly studied profession. Studies support midwifery care, and show excellent safety, utilization of resources and patient satisfaction levels.
"Every study that has compared midwives and obstetricians has found better outcomes for midwives for same-risk patients. In some studies, midwives actually served higher risk populations than the physicians and still obtained lower mortalities and morbidities. The superiority and safety of midwifery for most women no longer needs to be proven. It has been well established." (Madrona, L. & Madrona, M. (1993). The Future of Midwifery in the United States, NAPSAC News, Fall-Winter, p.30.
I. Quality of Care: Certified nurse-midwives caring for low risk women improve the infant mortality rate while lowering the cesarean section rate, both in hospitals and birth centers, compared to physicians caring for equally low-risk women.
A. Birth certificate data from 1991 was examined for all singleton vaginal deliveries between 35 and 43 weeks. After controlling for socio-demographic and medical risk factors, the outcomes for physicians and nurse-midwives were compared:
The risk for neonatal mortality was 33% lower for births attended by CNMs.
The risk of delivering a low birth weight infant was 31% lower for CNM attended births.
The mean birth weight was 37 grams higher for CNM attended births.
The infant mortality rate was 19% lower for CNM attended births.
[Source: MacDorman, M.F. & Singh, G.K. (1998). Midwifery care, social and medical risk factors, and birth outcomes in the US. Journal of Epidemiology and Public Health, 52(5), 310-317]
B. Examining differences in the practices of family physicians, obstetricians and certified nurse-midwives caring for low-risk women, the authors found the following:
The cesarean section rate was 8.8% for nurse-midwives.
The cesarean section rate was 13.6% for obstetricians.
The cesarean section rate was 15.1% for family physicians.
Nurse-midwives used 12.2% fewer resources than either group of physicians.
[Source: Rosenblatt, R. A., et.al. (1997). Interspecialty Differences in the Obstetric Care of Low-Risk Women. American Journal of Public Health 387(3): 344-351]
C. Patients of certified nurse-midwives were much less likely to:
Have a variety of technological tools used to monitor or modify the course of labor.
Be continuously electronically monitored during labor.
Receive oxytocin to induce or augment labor.
Be given epidural anesthesia.
As a consequence, these factors appeared to result in fewer CNM patients having an operative delivery. The lower rate of cesarean sections is associated with shorter hospital stays and reduced health care cost.
[Source: Rosenblatt, R. A., et.al. (1997). Interspecialty Differences in the Obstetric Care of Low-Risk Women. American Journal of Public Health 387(3): 344-351]
II. Cost of Care: Health care payors benefit because nurse-midwifery care is cost effective. Lower costs associated with nurse-midwifery care include:
Lower payroll costs for staff model HMOs.
Lower rates of intervention.
Shorter lengths of stay in hospitals.
Use of birth centers instead of hospitals lowers costs even further.
Planned home births eliminate hospital costs entirely.
[Source: Gabay, M and Wolfe, SM. (1995) Encouraging the use of nurse-midwives: a report for policy makers. Public Citizen's Health Research Group.
Source: Gabay, M and Wolfe, SM. (1997) Nurse-midwifery: The beneficial alternative. Public Health Report, 112(5):386-94.]
THE EVIDENCE FOR CAREGIVER SUPPORT FOR WOMEN DURING CHILDBIRTH
Fourteen trials, involving more than 5000 women, were recently reviewed by the highly respected Cochrane Pregnancy and Childbirth Group, concluding that continuous support during labor has many benefits. The authors state that "this support should include continuous presence, the provision of hands-on comfort and encouragement." Studies have shown that continuous support:
Reduces the chances of having a C-section
Reduces epidural or other painkiller use
Reduces use of oxytocin (Pitocin)
Reduces the duration of labor
Reduces the use of forceps and vacuum extraction
Reduces the chances of health complications and hospitalizations
[Source: Hodnett, E.D. (1998). Support from caregivers during childbirth. Cochrane Review, Issue 2. Oxford Update Software, updated quarterly.]
BIRTH CENTER CARE
I. "The National Birth Center Study" reported on the outcomes of care for 11,814 women who were admitted in labor. Results included:
1. No maternal mortality.
2. Neonatal mortality of 1.3 births/1000; 0.7/1000 if lethal anomalies were excluded. These rates are comparable to studies of low risk in-hospital births.
3. Cesarean section rate of 4.4%, approximately one-half that of studies of low risk in-hospital births during the time period studied.
[Source: Rooks, J.P.,et.al. (1989) Outcomes of care in birth centers: The national birth center study. New England Journal of Medicine 312:1804-1811.]
II. Cost Savings: Cost comparisons of Birth Center vs. Hospital Costs: If just 100,000 births were attended in birth centers, not only would access to care greatly improve, annual savings could total nearly $314 million. In addition, for every 1,000 non-cesarean births at birth centers, it is estimated savings could equal $17.4 million. These savings to healthcare payors have been demonstrated over more than two decades of birth center operations. Highlights of birth center cost savings include:
All charges include professional and facility fees.
Birth Center charges are based on an average stay of 9 hours postpartum and include a comprehensive educational program for early discharge and careful and continuous home follow-up.
Hospital charges for vaginal birth are based on a stay of 48 hours postpartum and include ancillary charges.
Hospital charges for cesarean birth care based on a stay of 72 hours postpartum and include ancillary charges.
[Sources: Health Insurance Association of America and National Association of Childbearing Centers.]
OTHER RESEARCH ON OUT-OF-HOSPITAL BIRTH
I. Research on out-of-hospital birth demonstrates that the safety of home (and by extension) birth center births depends on these factors:
A. The birth setting is planned (outcome data should not include unplanned home births such as preterm birth, which are inherently high risk and often unattended by a competent provider).
B. Appropriate screening for risk is consistently performed. In studies that include high risk situations such as breech and twin births, mortality rates exceed the national average. In studies that include only low-risk women, outcomes are as good or better than low risk hospital births. In the Netherlands, where 30-40% of babies are born at home, a defined set of risk criteria known as the Kloostermanlist, is routinely used, with very good outcomes. Lewis Mehl-Madrona and Morgaine Mehl Madrona underscored this point in a study comparing midwives who delivered post-dates, twin and breech births at home with family physicians whose home birth practice "risked out" these clients. The family physicians had better outcomes, but outcomes were equal when the higher risk pregnancies were dropped from the midwife data set. Mehl-Madrona noted that "births involving these conditions are associated with higher perinatal mortality regardless of the place of birth" and that "bad outcomes of high-risk home births hurt babies, parents, individual midwives, and the midwifery and home birth movements".
[Source: Mehl-Madrona, L. & Madrona, M.M. (1997). Effects on outcomes of attending breeches, twins, and post-dates pregnancies at home. Journal of Nurse-Midwifery 42(2):91-98].
II. Some examples of research demonstrating the safety of home birth include:
A. In the Netherlands, where 40% of babies are delivered at home, a prospective analysis of 54 midwifery practices and 1,836 women with low risk pregnancies demonstrated that planned home birth was as safe for primiparous women and significantly safer for mulitparous women than planned hospital birth. The authors conclude that "it is important, therefore, that the home birth option remains available, but especially that women at low risk are really given a free choice."
[Source: Wiegers, T., Keirse, M, vander Zee, J, and Berghs, G. (1996). Outcome of planned home and planned hospital births in low risk pregnancies: prospective study in midwifery practices in the Netherlands. British Medical Journal, 7068(313)]
B. In a study using matched cohorts, US women beginning care with midwives in out-of-hospital settings had cesarean section rates considerably lower than similar women cared for by physicians in hospitals. The lower cesarean section rate involved no compromise in mortality and morbidity outcome measures. This study explores the links between midwifery knowledge/support and lowered cesarean section rates and encourages policy-makers to consider expanding access to midwifery care and out-of-hospital settings.
[Source: Sakala,C. (1993) Midwifery care and out-of-hospital birth settings: how do they reduce unnecessary cesarean section births? Social Science and Medicine, 37(10):1233-50]
C. A study comparing home birth by midwives in "The Farm" practice (including Ina May Gaskin) with hospital deliveries during the same time period (1971-1989) concludes that home births with non-nurse midwives can be as safe as hospital birth, and with fewer interventions.
[Source: Duran, A.M. (1992)The safety of home birth: the farm study. American Journal of Public Health. 82(3): 450-453]
D. Twenty-nine nurse-midwifery practices with births of 1,404 women over four years found that mortality and morbidity rates equal those of low risk women in the hospital. The authors emphasize that good outcomes are the result of "qualified practitioners and within a system that facilitates transfer to hospital care when necessary."
[Source: Murphy, PA & Fullerton, J. (1998). Outcomes of intended home births in nurse-midwifery practice: a prospective descriptive study. Obstetrics and Gynecology, 92(3): 461-70]
E. Matched pairs of Swiss mothers delivered either in the home or hospital setting. The home birth group needed significantly less medication and fewer interventions and outcomes were equally as good as women who delivered in hospitals. The authors conclude that "healthy low risk women who wish to deliver at home have no increased risk either to themselves or to their babies".
[Source: Ackermann-Liebrich, U., Voegli, T., Gunter-Witt, K., et al. (1996) Home versus hospital deliveries: follow up study of matched pairs for procedures and outcome. British Medical Journal, 7068(313.)]
III. Two studies reflecting the need for rigorous methodology when looking at out-of-hospital birth, and which are often cited by physicians to demonstrate that out-of-hospital birth is not safe:
A. The Pang study. This study looked at Washington State birth certificate data and retrospectively compared home and hospital births from 1989-1996. The study found that the risk for neonatal death doubled for home versus hospital births. This study was widely publicized by the American College of Obstetricians and Gynecologists (ACOG) before researchers discovered methodological flaws, which went un-noticed in the press. Critics point out that the study relies on birth certificate data that does not include information on the intended place of birth, and that there were likely a number of unplanned and unattended home births included in the data set. In particular, the intrapartum transfer rate was abnormally low in the Pang study (half of what most studies cite), indicating a high percentage of unplanned and unattended home births. With a large body of well-conducted studies across many cultures indicating that planned out-of-hospital birth is safe, the Pang study raises questions about appropriate research methods and the politics of birth.
[Source: Pang, J., et al. (2002). Outcomes of planned home birth in Washington State. Obstetrics and Gynecology, 100(2): 253-9.
B. The Australian study. An Australian study on planned home birth between 1985-1990 found a higher intrapartum death rate than hospital births in Australia and home births in other countries. The study states that the two largest contributors to the higher mortality rates were the "underestimation of the risks associated with post-term birth, twin pregnancy and breech presentation, and a lack of response to fetal distress". This study illustrates the point that high risk pregnancies have inherently higher risks of poor outcomes and are safer delivered in the hospital.
[Source: Bastian, H.& Keirse, M.J. (1998) Perinatal death associated with planned home birth in Australia: population based study. British Medical Journal. 317(7155): 384-8]
OTHER RESEARCH ON QUALITY OF CARE Baldwin, L.M., et.al. (1994). Do Providers adhere to ACOG standards? The case of prenatal care. Obstetrics & Gynecology;84:549-55
Bell, K. and Mill, J.I. 1989). Certified nurse-midwife effectiveness in the health maintenance organization obstetric team. Obstetrics & Gynecology 74:112-116.
Butler, J.et.al. (1993) Supportive nurse-midwife care is associated with a reduced incidence of cesarean section. Obstetrics & Gynecology 168:1407-1413.
Davis, Lorna G., et.al. (1994.) Cesarean section rates in low-risk private patients managed by certified nurse-midwives and obstetricians. Journal of Nurse-Midwifery 39:91-97.
Greulich, B., et.al. (1994). Twelve years and more than 30,000 nurse-midwife-attended births: the Los Angeles County & University of Southern California Women's Hospital Birth Center experience. Journal of Nurse-Midwifery 39:185-196.
Haire, D. and Elsberry, C. (1991). Maternity care and outcomes in a high-risk service: the North Central Bronx Hospital experience. Birth 18:33-37.
Harvey, S., et.al. (1996). A randomized controlled trial of nurse-midwifery care. Birth 23:128-135.
Hueston, W.J. & Rudy, M. (1993). A comparison of labor and delivery management between nurse-midwives and family physician providers. Journal of Family Practice 375:449-454.
Knedle-Murray, M.E., et.al. (1993). Production process substitution in maternity care: issues of costs, quality, and outcomes by nurse-midwives and physician providers. Medical Care Review 50:91-112.
Oakley, D. (1996)Comparisons of outcomes of maternity care by obstetricians and certified nurse-midwives. Obstetrics and Gynecology 88:823-829.
Turnbull, D., et.al. (1996). Randomized, controlled trial of efficacy of midwife-managed care. Lancet 348:213-218.
CLASSIC HISTORICAL ARTICLES Gatewood TS and Stewart JB. (1975). Obstetricians and nurse-midwives: the team approach to private practice. American Journal of Obstetrics and Gynecology 123:35-40
Hellman L. and O'Brien F. (1964). Nurse-midwifery An experiment in maternity care. Obstetrics and Gynecology, 24:343-49.
Mann RJ. (1981). San Francisco General Hospital nurse-midwifery practice: The first thousand births. American Journal of Obstetrics and Gynecology 140:676-82
Mayes F, et.al. (1987). A retrospective comparison of certified nurse-midwife and physician management of low risk births. Journal of Nurse-Midwifery 32:216-221.
